Internet Service Providers (“ISP”) provide access to the Internet to dial-up clients over the Public Switched Telephone Network (“PSTN”). Typically, the ISP also provides access to a mail server. The mail sever stores mail messages for the client in a client mailbox. The mail server may be in the same server as the ISP or in a remote server which communicates with the ISP over a data network.
To access the client mailbox, the dial-up client dials the ISP's telephone number. After the phone call is connected, the dial-up client logs into the mail server and can access mail messages stored in the client mailbox. The dial-up client can only determine if a new mail message has been stored in the client mailbox after the call is connected and the client has logged into the mail server. This involves connecting the dial-up client and the ISP for a time period typically greater than one minute.
While the dial-up client is connected to the ISP, phone charges may be incurred for the telephone call. Also, because the connection between the ISP and the dial-up client, is a dedicated connection, this connection cannot be used by another dial-up client. Thus, congestion may occur at peak periods, as large numbers of clients attempt to connect to the ISP, in order to determine if a new mail message has been delivered to their mailboxes.